Electric switch



Jan. 15, 1963 J. SCHMIER ETAL 3,073,933

ELECTRIC swrrcn Filed May 29, 1959 3 Sheets-Sheet 1 INVENTORS JACOB SCHMIER HAROLD P LEWIS ATTORNEY Jan. 15, 1963 J. SCHMIER ETAL 3,073,933

ELECTRIC SWITCH Filed May 29, 1959 3 Sheets-Sheet 2 A 2 2 26 G C Z 20 H I40 FIG. 5.

/ 24 D Z 2 G c F E &

ll 36 H INVENTORS JACOB SCHMIER HAROLD P. LEWIS BY ATj'O RNEY INVENTORS JACOB SCHMIER HAROLD I? LEWIS ATTORNEY Jan. 15, 1963 J. SCHMIER ETAL ELECTRIC SWITCH Filed May 29, 1959 s Sheets-Sheet a States atent 3,073,933 ELECTRIC SWITCH .Iacob Schmier, Allentown, and Harold P. Lewis, Newtown, Pm, assignors to Rodale Manufacturing Co., Inc, Emmaus, Pa., in corporation of Pennsylvania Filed May 29, 1959, Ser. No. 816,789 4 Claims. ($1. 200-456) Our invention relates to an electric switch, wherein a push button controls the electrical circuit; whereby repeated pressing of the push button inwardly causes the electrical contacts to alternately close and open depending upon the configuration of a cam that controls the movement of one of a pair of contacts.

The primary object of our invention is to construct a shallow electric switch wherein a ratchet wheel is securely mounted on the same shaft that carries a cam that engages one of the electrical contacts and wherein a pawl for actuating the ratchet wheel will always be in correct position to actuate the ratchet wheel.

In the manufacturing of an electric switch for the home, we have discovered that the bend in the flexible contact which is engaged by a cam is not constant due to variations in the thickness of metal. The metallic alloy from which the flexible contact arm is stamped is not absolutely constant thereby resulting in varying thicknesses of the bend. Better control is obtained of the movable contact arm on which the electrical contact is firmly mounted by having the metal for the movableor flexible contact arm made without any sharp bends therein and having a portion of the flexible contact arm which is to be engaged by the cam straight.

Heretofore, we have found that by touching one side of the push button, there may be a tendency to bind and that the push button generally does not move in a rectilinear direction along the shaft. With the elongated bore in the center of the push button of our present invention, the push button can move'in a direct rectilinear direction so that the touching of the button at any place on the outer surface of the button will not tilt the button.

It is, therefore, an object of our invention to provide a switch which is simple in construction and which has relatively few parts as contrasted with our switch as set forth in our Patent No. 2,820,113.

Another object of our invention is to provide a simple switch which has a relatively small number of parts and which is easily and accurately assembled.

Another object of our invention is to provide an electric switch wherein a ratchet wheel is actuated by a pawl which is of a length whereby the pawl will always be tangent to the circumference of the ratchet wheel.

Another object of our invention is to provide a switch which will carry a heavy load over a relatively long period of time without being rendered inoperable.

Another object of our invention is to provide a push button wherein there is an elongated bore in the center thereof which moves the push button along a shaft only in a rectilinear direction.

Another object of our invention is to provide a push button wherein there is an elongated bore which is adapted to fit over a shaft wherein the push button cannot tilt with respect to the longitudinal axis of the shaft.

Another object of our invention is to provide an electrical switch wherein the actuating pawl for a ratchet wheel cannot be tripped into a non-operating position.

Another object of our invention is to provide a touch button electrical switch wherein the actuating pawl for a ratchet wheel will always be guided into its proper path of travel.

In order to achieve the objects of our invention, we provide a push button electric switch having a pawl, a complementary ratchet wheel mounted upon the same shaft carrying a cam, wherein the pawl, which is pivotally mounted, also acts to rotate the ratchet wheel one tooth at a time, together with its complementary cam; and the push button when returned to its initial position, will enable the spring pressed pawl to pivot itself so that it will pass a ratchet tooth and be in position to actuate the next ratchet tooth.

Other objects of our invention are to provide an improved device of the character described, that is easily and economically produced, which is sturdy in construction, and which is highly efficient in operation.

With the above and related objects in view, our invention consists in the detail of construction and combination of parts, as will be more fully understood from the following description, when read in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view of an electrical push button switch embodying our invention.

FIG. 2 is a plan view of our switch with the cover removed.

FIG. 3 is a perspective view of the switch casing itself.

FIG. 4 is a perspective view of the pawl alone.

FIG. 5 is a fragmentary sectional view of the electrical switch showing the electrical circuit in open position when along the line 55 of FIG. 1.

FIG. 6 is a view similar to FIG. 5 wherein the button has been pushed downwardly and the circuit closed.

FIG. 7 is an enlarged perspective view of the pawl and complementary ratchet wheel and detent stop.

FIG. 8 is a sectional view taken along line 88 of MG. 1 through the switch.

FIG. 9 is another sectional view taken along the modified type of switch having the push button illustrated in FIG. 11 showing tthe pair of electrical contacts and the pentagonal cam for actuating one of the contacts.

FIG. 10 is an enlarged view showing the flexible contact and the penta-surface cam.

FIG. 11 is a sectional view of the push button.

Referring now in greater detail to the drawing, we show a casing, generally designated as A, of molded insulation material, such as a phenolic resin product. Upon the casing A is a molded plate 10, which may have-a metal wall box mounting plate 12 mounted thereon. Aligned rectangular openings are'in the cover 10 and the plate 12 whereby a push button, generally designated as B, may move back and forth in a rectilinear direction.

Suitably mounted within the casing is a shaft 14, which carries a cam, generally designated as C, which has lobes thereon in order to actuate or move an electrical contact arm, generally designated as D. A fixed contact arm, generally designated as E, is adapted to have the contact button thereon engaged by'the contact button on the contact arm I) whereby the electrical circuit through the switch may be completed. These contacts have been described in greater detail in our previously filed patent application, Serial No. 681,993, filed September 4, 1957, now Patent No. 2,928,920, March 15, 1960.

A ratchet wheel, generally designated as F, is mounted upon the shaft 14 which also carries the cam C. However, the shaft, the ratchet wheel, and the cams may be integrally molded together so that the shaft and the ratchet wheel move in unison.

The push button G, guided in the opening in the cover and the mounting plate 12, has a central internal bore 62 defined by an elongated hollow integrally formed cylindrical extension 64 which slides upon a fixed. shaft 20. The shaft 20 also has encircling it a spring 22, which presses a pawl, generally designated as G, against the lower surface 24 of the push button B.

The upper end of the pawl G has an extension or tail 28 which can oscillate about the hump 30 around the bottom 24 of the push button B, The sides 23A, 28A are adapted to engage the sides 26 of the push button so .that the pawl G cannot rotate'from side to side about the shaft 29 at its axis, but must only move in one plane. A central opening 28 through the pawl G enables the pawl G to freely move vertically about the shaft 20. An extension 36 is stamped or pressed at an angle from the portion 35 of the pawl G and the extension 36 actually moves the ratchet wheel when the push button B is moved inwardly, as shown in FIG. 2. On its outwardly direction, the push button and the pawl B move upwardly against the ratchet wheel but the detent, generally designated as H, shown in FIGS. 5, 6, and 7, prevents the ratchet wheel from moving in one direction by virtue of the detent engaging one tooth of the ratchet wheel.

The portion 35 of the pawl rests against the cam teeth P so that there is always some part of the pawl G in contact with the ratchet wheel.

The lower end portion 38 of the pawl G is extended to prevent the ratchet wheel contact portion 36 from being trapped in a non-operating position as would be the case if the free end 38 of the pawl would move vertically over the center of the shaft 14.

To prevent the ratchet wheel from moving in one direction, the spring-like detent H lightly engages the lowermost teeth in the ratchet wheel E.

In FIG. 5, we show a flexible electric contact arm D1, which is anchored at its end 40. The flexible contact D1 is made of a single metal stamping and it is firmly anchored' at its end 40. From the end is an adjoining bend 42, which, jointed to an off-set portion 44, to continue to a straight elongated extension 46. The connecting portion 48 of the flexible contact is connected to an off-set free end 50 that carries an electrical contact button 52. It should'be noted that a portion of the elongated straight portion 46 ofthe flexible arm is adapted to be engaged by one of the flat surfaces of the pentagonal cam F1. The cam F1 and five flat surfaces defined by the straight faces 54, 55, 56, 57 and 53. It should be noted that as the shaft 14 on which the cam F1 is mounted, is rotated, the junction of two of the adjoining faces moves a greater distance from the center of the shaft 14 than the flat penta surface. Viewing FIG. 9, the contact 52 is lifted away from the contact fixed terminal E1, by virtue of the edge of adjoining penta surfaces engaging the electrical contact 51 along the flat connecting surface 48.

The flexible contact arm D1 is anchored at one end and by virtue of the bends therein its length is extended to be freely flexible.

The modified push button, generally designated as B1, is molded of insulating material and it has a flat outer surface 60 and it has a central internal bore 62 defined by an elongated hollow integrally formed cylindrical extension 64. The push button also has an internal side recess 26 to provide for the reception of the free end of the pawl 28. It is to be noted that the distance from the surface 60 to the end of the cylindrical member 64 is almost three-quarters of the distance measured from the surface 69 to the interior bottom surface of the casing A.

By the construction heretofore explained, the push button always will move in a rectilinear direction even though the surface 60 on the push button is touched at its end to move it inwardly.

Hence, no binding of the parts for operating the contacts will occur.

The spring 22 reacts to any light touch upon the push button B1 to operate the pawl and its cam.

Although our invention has been described in considerable detail, such description is intended as being illustrative rather than limiting, since the invention may be variously embodied, and the scope of the invention is to be determined as claimed.

We claim:

1. In a switch having a rectilinear movable push button, a ratchet wheel, a pawlpivotally and resiliently mounted against the bottom of said push button, a shaft on which said wheel is mounted, a cam mounted on said shaft to rotate in unison with said ratchet wheel, a movable electrical contact in operative engagement with said cam, a stationary contact positioned to be engaged and disengaged by said movable contact in accordance with the rotation of said cam, one end of said pawl having an extension to engage and move said ratchet wheel and a portion of said pawl extending below said extension whereby a portion of said pawl will always be in abutment with said ratchet wheel.

2. The invention of claim 1 including a casing and a detent, to prevent the rotation of said ratchet wheel in one direction attached to said casing.

3. In a switch assembly, a casing constructed of electrically insulating material, an upright shaft in said casing, a movable push button which is movable toward and away from the interior of said casing and is slidingly telescoped over said shaft, said casing enclosing a ratchet wheel, a pawl pivotally and resiliently mounted against the bottom of said push button and in operative engagement with said ratchet wheel, a cam coaxially mounted with said ratchet wheel on a common rotatable shaft, a movable electrical contact operatively engaged with said cam, a stationary electrical contact positioned to be engaged and disengaged by said movable contact in accordance with the rotation of said cam, a spring assembly urging said push button away from the interior of said casing; and a hollow extension on said push button telescoped over said shaft and comprising a guide means for said spring assembly.

4. In a switch assembly, a casing construction of electrically insulating material, an upright shaft in said casing, a movable push-button which is movable toward and away from the interior of said casing and is slidingly telescoped over said shaft, said casing enclosing a ratchet wheel, a pawl pivotally andresiliently mounted against the bottom of said push button, with one end of said pawl having an extension to engage and move said ratchet wheel, and a portion of said pawl extending below said extension whereby a portion of said pawl will always be in abutment with said ratchet wheel, a cam coaxially mounted with said ratchet wheel on a common rotatable shaft, a movable electrical contact operatively engaged with said cam, a stationary electrical contact positioned to be engaged and disengaged by said movable contact in accordance with the rotation of said cam, a spring assembly urging said push button away from the interior of said casing, and a hollow extension on said push button telescoped over said shaft and comprising a guide means for said spring assembly.

References ited in the file of this patent UNITED STATES PATENTS 1,753,029 Sparks et al. Apr. 1, 1930 2,048,451 Johnston July 21, 1936 2,572,335 'rlafke Oct. 23, 1951 2,885,515 Bentley et al. May 5, 1959 2,933,578 Hubbell et al. Apr. 19, 1960 FOREIGN PATENTS 950,617 France Oct. 3, 1949 

1. IN A SWITCH HAVING A RECTILINEAR MOVABLE PUSH BUTTON, A RATCHET WHEEL, A PAWL PIVOTALLY AND RESILIENTLY MOUNTED AGAINST THE BOTTOM OF SAID PUSH BUTTON, A SHAFT ON WHICH SAID WHEEL IS MOUNTED, A CAM MOUNTED ON SAID SHAFT TO ROTATE IN UNISON WITH SAID RATCHET WHEEL, A MOVABLE ELECTRICAL CONTACT IN OPERATIVE ENGAGEMENT WITH SAID CAM, A STATIONARY CONTACT POSITIONED TO BE ENGAGED AND DISENGAGED BY SAID MOVABLE CONTACT IN ACCORDANCE WITH THE ROTATION OF SAID CAM, ONE END OF SAID PAWL HAVING AN EXTENSION TO ENGAGE AND MOVE SAID RATCHET WHEEL AND A PORTION OF SAID PAWL EXTENDING BELOW SAID EXTENSION WHEREBY A PORTION OF SAID PAWL WILL ALWAYS BE IN ABUTMENT WITH SAID RATCHET WHEEL. 